Around 40 flights from England were expected in Porto during the day, with the first fans having arrived.
"Hopefully that plane is bouncing on the way back," said Manchester City fan Neal who travelled to Porto with his father and will head back home in the early hours of Sunday on a charter flight. "It's a great atmosphere."
Asked at the pre-match news conference what it was like to have to break his selection news to the players, Guardiola said: "Terrible. It's absolutely disaster, don't be a manager in your life."
The Spaniard said there were no words that he could conjure up to ease the pain for the players concerned.
He can also finally count on a fully fit Eden Hazard, who was in lively form in Saturday's 2-0 win over Osasuna and is in line to start at the ground which he called home for seven years before switching from Chelsea to Real in 2019.
Havertz and Ziyech started the first leg on the bench, but Tuchel has remained loyal to Werner since taking charge in January despite his lack of goals.